Commercial article printing typically occurs during the production of the article. For example, ball skins are printed with patterns or logos prior to the ball being completed and inflated. Consequently, a non-production establishment, such as a distribution site or retail store, for example, in a region in which potential product customers support multiple professional or collegiate teams, needs to keep an inventory of products bearing the logos of various teams popular in the area. Ordering the correct number of products for each different logo to maintain the inventory can be problematic.
One way to address these issues in non-production outlets is to keep unprinted versions of the products, and print the patterns or logos on them at the distribution site or retail store. Printers known as direct-to-object (DTO) printers have been developed for printing individual objects. These DTO printers have a plurality of printheads arranged in a vertical configuration with one printhead over another printhead. Some of these printers use UV curable inks to form ink images on the objects. UV curable inks require a UV radiation source that directs UV light onto the inks on the object surface. This light cures the inks and helps eliminate vapors that otherwise emanate from the inks. Some of these vapors can be noxious to humans.
One issue that affects the ability of the UV curing device to cure the UV curable inks is oxygen inhibition. Oxygen inhibition refers to the effect of atmospheric diatomic oxygen being present at the ink image as the UV light impinges on the image. Specifically, the oxygen affects the free radicals in the chain reactions that result in the curing of the UV inks. Methods for addressing oxygen inhibition are identified in Table 1 of “Mitigation of Oxygen Inhibition In UV LED, UVA and Low Intensity UV Cure” by Jo Ann Arceneaux, Ph. D., Allnex USA Inc., which was presented at uv.eb WEST 2015 in Redondo Beach, Calif. on Mar. 10, 2015. This table also identifies the advantages and disadvantages of these various approaches. While water-based UV curable inks are not as susceptible to oxygen inhibition, these inks do not always produce vibrant images on the objects. Thus, non-aqueous UV curable inks would require one of the methods set forth in the above-identified article with the attendant disadvantages. Enabling DTO printers to cure non-aqueous UV curable ink images on 3D objects without the effects of oxygen inhibition and the disadvantages of known oxygen inhibition remedies would be beneficial.